鄱阳湖流域赣江水系溶解态金属元素空间分布特征及污染来源

Spatial distribution and pollution source of dissolved metals in the Ganjiang River of Lake Poyang Basin

于2015年1月和7月在赣江干流和主要支流37个采样点共采集74个水样,分析赣江水系15种溶解态金属元素(Be、Al、V、Mn、Fe、Co、Ni、Cu、As、Mo、Cd、Sb、Tl、Pb、U)的空间分布特征和污染来源的贡献率.结果表明:多数水样的溶解态金属元素浓度符合水质标准,主要的超标元素是Fe,样品超标率为21.60%,其次为As(8.10%)、Mn(4.05%)、Tl(4.05%)和Al(1.35%).Be、Al、V、Fe、Co、Ni、Cu、U浓度在枯水期显著高于丰水期,其他元素差异不显著.依据溶解态金属元素的空间分布特征,赣江流域可分为3个区域:湘水、章水和赣江赣州市段(C1),桃江、袁水和锦江(C2),其他区域(C3);溶解态金属元素水平大小排序为C1>C2>C3,其中Be、Al、Cu、Mo、Sb、As浓度在C1最高,V、Mn、Fe、Ni、Cd浓度在C2最高.采矿废水、矿渣和农田土壤降雨淋滤、钢铁冶炼废水是赣江溶解金属元素的主要来源;Be、Al、Cu、Pb、U的污染源超过40%来自采矿废水,Cu、As、Mo、Cd的污染源超过35%来自矿渣和农田土壤降雨淋滤,V、Mn、Co、Ni的污染源超过41%来自钢铁冶炼废水.

We collected 74 water samples from 37 sites along the Ganjiang River and its tributaries in January and July,2015 to analyze the spatial distribution of dissolved metals( Be,Al,V,Mn,Fe,Co,Ni,Cu,As,Mo,Cd,Sb,Tl,Pb and U),and to estimate the contributions of pollution sources in Lake Poyang Basin. The results showed that the concentrations of dissolved metals in most water samples met the national water quality standards,and Fe is the primary trace metal beyond the national standard,i.e. 21. 60% of water samples had higher Fe concentrations than the national drinking water quality standard,followed by As( 8.10%),Mn( 4. 05%),Tl( 4. 05%) and Al( 1. 35%). In addition,the concentrations of Be,Al,V,Fe,Co,Ni,Cu and U during the dry season were significantly higher than those during the wet season,while others had no significant difference. Based on the spatial distribution of dissolved metals,three spatial regions were identified: C1( Xiangshui River Basin,Zhangshui River Basin and Ganzhou section of Ganjiang River),C2( Taojiang River Basin,Yuanshui River Basin and Jinjiang River Basin),and C3( the other regions beyond C1 and C2). The contamination order in the three regions was C1 > C2 > C3. The highest concentrations of Be,Al,Cu,Mo,Sb and As occurred in C1; while V,Mn,Fe,Ni and Cd in C2. The primary sources of dissolved metals in the Ganjiang River were mining waste water,leaching water of slag and agricultural soils,and steel industry waste water. We estimated that more than 40% of Be,Al,Cu,Pb and U were from mining waste water,more than 35% of Cu,As,Mo and Cd from leaching water of slag and agricultural soils,and more than 41% of V,Mn,Co and Ni from the steel industry waste water.